Power consumption of integrated circuits may be reduced and efficiencies may be increased by reducing operating voltages of the integrated circuits.
Some circuits are more amenable to lower operating voltages than others. Where integrated circuits within a system operate at lower voltages, conflicts or contention may arise between the circuits. These conflict and contention can be alleviated by level shifting the operating voltage of part of the circuits to higher voltage. But level shifting may introduce delays.
For example, an integrated circuit may include circuitry to pre-charge a node to a desired voltage level. The operating speed of the circuitry may depend upon the speed of the pre-charge circuitry. Where level shifting introduces a delay in the pre-charging, subsequent events, such as memory accessing, may be delayed.
Level shifting becomes more challenging when inputs to a circuit change between a plurality of operating voltages, such as where cores of a multi-core processor are controllable to operate and output logic at multiple voltage levels.
In the drawings, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears.